My Mazda Tribute has had the flipping gauge reading issues, which are now resolved. But it still misses like crazy even though I replaced plugs, coils/wires, etc. It looks like the PCM needs replacing. I am told before replacing it I need to have the "new" one flashed, to have it set to my particular vehicle. Any insights on this one? NAPA wants $210 for the PCM and $80 to flash it. My shade tree mechanic can install.